Body support cushioning system

ABSTRACT

A CUSHIONING FOR UNIFORMLY IDSTRIBUTING SUPPORT OF AN INVALID COMPRISING A LIQUID CONTAINER OF FLEXIBLE SHEET MATERIAL IMPERVIOUS TO THE FLUID, AND MEANS TO ELEVATE SIDE PORTIONS OF THE CONTAINER TO FORM A LOOSE UPPER SURFACE WHICH CAN CONFORM TO THE SUPPORTED BODY PORTIONS OF THE INVALID. THE CUSHIONING PORTION OF THE LIQUID CONTAINER COMMUNICATES WITH A RESERVOIR WHICH CAN BE RAISED AND LOWERED TO FILL AND DRAIN THE CUSHION AND CAN BE ELEVATED SUFFICIENTLY TO DEVELOP A HYDROSTATIC HEAD BALANCING THE   PRESSURE REQUIRED TO SUPPORT THE INVALID WHERE THE INVALID IS TO BE SUPPORTED WITH PRESSURES GREATER THAN THOSE IMPOSED ON A BODY FLOATING ON A FREE SURFACE. THE PAD CAN BE APPLIED TO WHEEL CHAIRS BY PROVIDING A RESERVOIR EXTENDING UP THE BACK OF THE CHAIR.

June 22, 1971 M. eri-FRIED EI'A'L BODY SUPPORT CUSHIONING SYSTEM Filed Aug. 28, 1968 2 Sheets-Sheet 1 INVENTORS MAX GOTTFRIED DENNIS G. MOSINIAK ANSIS V. TENTERIS ATTORNEYS BODY SUPPORT CUSHIONING SYSTEM Filed Aug. 28. 1968 2 Sheets-Sheet 2 INVENTORIS MAX GOTTFRlED DENNIS G. MOSINIAK ANSIS V. TENTERIS ATTORN EYS United States Patent O1 3,585,661 BODY SUPPORT CUSHIONING SYSTEM Max Gottfried, Rossford, and Dennis G. Mosiniak and Ansls V. Tenteris, Toledo, Ohio, assignors to The Jobst Institute, Inc., Toledo, Ohio Filed Aug. 28, 1968, Ser. No. 756,074 Int. Cl. A47c 27/08 US. Cl. 5348 13 Claims ABSTRACT OF THE DISCLOSURE A cushion for uniformly distributing support of an inval d comprising a liquid container of flexible sheet material impervious to the fluid, and means to elevate side portions of the container to form a loose upper surface WhICh can conform to the supported body portions of the invalid. The cushioning portion of the liquid container communicates with a reservoir which can be raised and lowered to fill and drain the cushion and can be elevated sufliciently to develop a hydrostatic head balancing the pressure required to support the invalid where the invalid is to be supported with pressures greater than those imposed on a body floating on a free surface. The pad can be applied to wheel chairs by providing a reservoir extending up the back of the chair.

BRIEF SUMMARY OF THE INVENTION This invention relates to body support pads and particularly to cushioning means for supporting invalids.

Bed sores or decubitus ulcers are usually attributed to the occlusion of the blood supply to areas of support Where high pressures are developed. In particular, when the surface pressure exceeds the pressure distributing the lymph fluid, a starvation of the cells occurs. In order to avoid those points of pressure in immobile patients, it has been proposed to support them on a Water bed wherein a body of water of suflicient depth and volume to float the patient is covered with a sheet of water impervious material which is sufficiently loose to conform to the patients body and permit him to sink to a level at which he in effect floats. In such circumstances the maximum pressure applied at any point on the patients body is below the interstitial pressure of the lymph. However, such water beds are extremely cumbersome and expensive and a patient can be ministered to in such a bed only with difliculty. The water cushion principle has not been applied to more restricted cushions such as chairs since the patient would sink too deeply to be comfortable when maintained in a seated position.

The present invention contemplates a water cushion which while applying an essentially uniform pressure over the area of support for the patient utilizes a hydrostatic head to increase the pressure above that imposed on a floating patient. Ideally this pressure is maintained below the to 15 millimeters of mercury per square centimeter of the human bodys interstitial pressure by permitting a restricted sinking of the patient into the water cushion as determined by adjustment of the hydrostatic head within the cushion.

A reservoir communicates with the cushion so that in a mattress application the pressure at the upper surface of the cushion can be that at a free surface or can be maintained at a desired hydrostatic head by adjusting the elevation of the reservoir. When the patient is to be ministered to the cushion can be drained into the reservoir by lowering the reservoir below the level of the underlying bed mattress thereby removing the enfolding cushion from the patient and lowering the patient to the more rigid underlying bed mattress. When the treatment of the patient permits, the cushion can be filled to gradu- 3,585,661 Patented June 22,, 1971 ally lift the patient free of the mattress by raising the reservolr.

Optimization of pressure distribution over the supporting areas of a seated patient can also be accomplished with a liquid filled seat cushion wherein a reservoir is coupled to the cushion and mounted on the back or arms of the seat to provide the requisite head to raise the patient free of the underlying supporting surface.

PRIOR ART Heretofore it has been known to support patients in a container filled with water and covered loosely with a water impervious sheet. Usually the patient is supported in the main by the water and in part by tension on the sheet covering. Mattresses have been made of liquid impervious material and filled with water to permit a restricted yielding due to the redistribution of the essentially incompressible liquid within the confines of the closed container forming the mattress as shown in Luria Pat. 665,243 of Jan. 1, 1901 for Medical Bed, and Stevenson Pat. 1,306,787 of June 17, 1919 for Mattress.

Hall proposed a Hydraulic Bed in Pat. 1,212,479 of Ian. 16, 1917 including a mattress made up of a rigid frame and bottom covered by a water impervious flexible sheet material sealed to the rigid frame. The rigid frame includes an integral expansion tank into which liquid within the mattress may rise when weight is imposed on the flexible sheet. The rigidity of the mattress is controlled by the head of liquid established in the expansion tank.

Each of these prior art devices is heavy due to the quantity of liquid required for effective patient support, cumbersome, expensive, difiicult to store and transport, and presents the patient supported on the mattress in a state in which he is diflicult to treat due to the tendency of the flexible cover to enclose and envelope the patient. Further, none of these devices lends itself to application to conventional bed and chair constructions.

An object of the present invention is to optimize the supporting pressure distribution of cushions for invalids.

Another object is to simplify the care of patients supported upon an encompassing cushion.

Further objects are to reduce the complexity, bulk and expense of a cushion system offering a floating support.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a bed and mattress supporting a mattress cushion, liquid reservoir and elevating means for the reservoir all according to this invention;

FIG. 2 is a side elevation of a bed cushion according to this invention showing in phantom the position of the patient when supported free of the underlying mattress by the cushion;

FIG. 3 is a cross-section of the bed of FIG. 2 taken along the line 33 to show how the loose upper surface of the filled cushion conforms to the patients body to float the patient;

FIG. 4 is a view corresponding to FIG. 3 showing the drained cushion and the support of the patient on the bed mattress;

FIG. 5 is an end view of another form of flotation cushion wherein the raised sides of the cushion envelope provided the reservoir to be raised and lowered for drainage and filling the cushion;

FIG. 6 is an end view of the cushion of FIG. 5 with the sides lowered to drain the patient support area and expose the patient for convenient treatment;

FIG. 7 is a side elevation of a wheel chair of conventional form having a flotation cushion with a reservoir extending up the back of the chair; and

FIG. 8 is a front view of the chair of FIG. 7 on a reduced scale sectioned along the line 8-8 of FIG. 7

to show the conformation of the seat cushion to the legs of an occupant.

DESCRIPTION OF THE PREFERRED EMBODIMENT The cushions of the present invention are applicable to conventional beds and seats or can be incorporated in special constructions. Generally they involve structures made up of a fluid impervious envelope having upper and lower walls of the same shape and size bonded near their margins and filled with a fluid having the same general density as the human body. Water is a suitable and readily available filling fluid. The envelope is made with a lateral surface when unconfined substantially wider than the area to be cushioned so that when confined to the area and turned upward at the sides of the area, the upper surface of the cushion is loose and may even fold over on itself in some regions. Fluid within the envelope in raising the upper surface between its raised sides further relaxes the upper surface whereby a body placed on that surface tends to sink into the surface and the sheet material thereof conforms to the body in a manner cloSely approximating the conformity of unrestrained liquid to a body immersed therein.

In order to limit the degree to which the body is immersed and to reduce the quantity of fluid required for flotation, the raised sides of the envelope can be constrained to permit fluid to rise in those sides above the supporting surface of the cushion without ballooning. Such arrangements enable a hydrostatic head to be established at the support surface whereby the supporting forces are substantially uniformly distributed over the surface of the body placed on the surface and yet those forces are greater than the forces when the body is floating on a free surface.

FIG. 1 shows a bed having a headboard 11, a footboard 12, and side boards 13 embracing a suitable mattress 14 which can be supported on springs (not shown).

A mattress cushion according to the invention comprises an envelope 15 of the general lateral extent of the underlying bed mattress 14 of conventional form utilized with hospital beds in length and of a width greater than the support area by an amount sufficient to permit its lateral sides to be raised and form a pool of liquid of a depth suflicient to lift the patient free of the underlying mattress. Cushion envelope 15 is made up of a first wall 16 for supporting engagement with the body and a second wall 17 engaging the underlying supporting bed mattress. The walls are coupled to each other in a liquid impervious manner such that the envelope 15 is in the general form of a liquid impervious sack. A treated fabric such as rubber or neoprene coated nylon can be employed for walls 16 and 17. The mode of supporting a patient is to utilize a liquid, usually water, as a filler for the cushion in a quantity just sufficient to raise all portions of the prone patients body free of the mattress 14 by separating wall 16 from Wall 17 at all points while wall 16 con forms to the patients body. This insures that the liquid applies essentially uniform supporting pressure to all supported surfaces of the patients body, disregarding differences in pressure due to differences in liquid head within the mattress.

Walls 16 and 17 of envelope 15 are jointed to form an elongate pocket 18 along their longitudinal sides so that the cushion can be suspended from side rails 19. The pendent portion 20 of the cushion envelope or extension portion adjacent the body support region of the cushion provides the slack upper surface of the envelope. A frame supports rails 19 and constrains ballooning laterally as liquid is introduced into the envelope following its mounting on the bed 10. Upright stanchions 21 having suitable brackets 22 mount end rails 23 and side rails 19. End rails 23 provide structural rigidity to the frame. Intermediate side rails 24 are supported from stanchions 21 by brack- 4 ets 22 at spaced positions to limit ballooning of the cushion envelope.

As shown in FIG. 1 the upper surface 16 of the cushion envelope is caused to fold upon itself when fluid is introduced into the envelope. This loose surface permits a patient to sink into the enveloped pool of liquid and have the surface 16 generally conform to his body as represented in FIGS. 2 and 3. The fabric available to conform to the patient on the upper surface across the width of the support area is approximately twice the depth of the liquid in the support area.

A reservoir 25 which may be of the same sheet material as the cushion envelope 15 is arranged in direct communication with envelope 15 through the conduit 26. Conduit 26 may be an extension of the envelope 15 and reservoir 25 and should permit the free vertical motion of the reservoir 25 without disturbing the portion of envelope 15 supporting the patient.

While the patient is floating on the cushion he is relatively inaccessible for treatment. In order to treat the patient conveniently, he is lowered to the underlying mattress 14 as shown in FIG. 4 by draining all or substantially all of the liquid from the cushion. Reservoir 26 is lowered to receive the liquid from the cushion during such treatment and is raised to return the patient to a cushion supported condition.

Reservoir 25 is shown supported by corner stanchions 27 upstanding from a platform 28 mounted on an elevating mechanism 29 to enable the reservoir to be raised and lowered to fill and drain the cushion. For example grommets (not shown) can be formed in the overlapping seams at the corners of reservoir 25 and can be engaged with hooks (not shown) in the corner stanchions to constrain the reservoir.

Elevating mechanism 29 can be of any suitable form. The platform 28 is shown as having fixed nuts 31 at its opposite ends engaged by lead screws 32 which can be rotated as by an electric motor 33 driving a coupling shaft 34 through bevel gears 35.

In practice the reservoir 25 has a capacity for sufficient liquid to fill the cushion 15, the conduit 27, and yet retain a quantity of liquid providing a head to float the patient when raised to the position shown in FIGS. 1 and 2. With the reservoir filled and the elevator lowered so that the cushion 15 is drained and collapsed to conform to mattress 14, the patient is placed on the cushion 15. When any treatment of the patient such as bathing requiring maximum mobility and accessibility to a maximum body area is completed, the patient is raised from the mattress by raising reservoir 25 with elevator 28. As the reservoir is raised, liquid flows into cushion 15 and gradually brings the fabric of its covering into conforming contact with the patient such that a vertical component of support is imposed on virtually all of the patients supportable body surface. A balance is developed between applied pressure and the area of support for a given weight such that all portions of the patient are raised free of the underlying mattress and thus the equalization of liquid pressure is imposed on the patient. The control of this pressure by the elevation of the reservoir enables it to be limited so that the patient is free of the mattress 1-4 without applying such pressure that the cushion is made harder than necessary to support the patients weight.

The elevating mechanism can be arranged with a rope or cable sling to overhead supports and counterweights (not shown) where the bed cushion is to be applied to a bed not having the elevator shown. Thus the fabric cushion can be emptied of liquid, folded and readily transported or stored as for use use in the home, with a minimum of special equipment.

Another and still simpler form of bed cushion and reservoir which can be raised and lowered is shown in FIGS. 5 and 6. In this embodiment the pendent sides of the cushion 36 are the reservoir, so that when the sides are raised, the liquid in the cushion distributes itself over the supporting mattress 14 at a level dependent upon the quantity present. In this position, the lower wall 37 of the envelope is stretched to provide a relatively smooth surface over the mattress and extending upward therefrom to the longitudinal marginal pockets 38 containing supporting side rails 39. The upper wall 41 is lifted free of the lower wall and thereby offers extra surface material across its width in the amount of twice the depth of the liquid. This extra material appears as the folds 42 in FIG. and is the means by which the cushion surface is permitted to conform to the patient in the manner shown in FIG. 3 to float the patient.

Sides of the envelope are suspended from stanchions 43 upon which hooks 44 or other suitable support brackets are formed to releasably receive the ends of the side rails 39 which protrude beyond the ends of pockets 38. These sides can readily be released by lifting the rails 39 free of the hooks 44 and permitting them to drop over the side boards 13 of the bed. This permits the liquid cushioning the patient to flow into the balloned pendent sides of the cushion thereby lowering the level of the liquid or completely draining the liquid from above the mattress 14 and exposing the patient on the relatively firm surface of the mattress for treatment. In practice it has been found that a nurse can raise and lower the sides of the cushion of FIGS. 4 and 5 as applied to a hospital bed. This has been done by releasing one corner at a time as by lifting the rail 39 from the hook 44 at the head of the bed and then from the hook 44 at the foot of the bed. Progressive shifting of the rail heights can also be accomplished by a unaided nurse to raise the side pocket reservoirs from the position shown in FIG. 6 to that of FIG. 5.

The concept of a unitary liquid impervious envelope of flexible sheet materials for a cushion, a reservoir and a coupling conduit for relief of concentrated pressure on the supporting surfaces of the body of an invalid is also applicable to chairs. As with the bed cushion, a unitary facing sheet can be employed for the cushion envelope wall, the conduit wall, and the reservoir wall so that top and bottom walls of all elements can be a single pair of registering sheets. While the body weight is supported on a smaller area for a seated patient than for a prone patient, and the pressures imposed when equalized over the supported surface are substantially greater than those for a prone patient, an optimized pressure distribution can be achieved using a balancing head. In such a utilization the minimized volume of liquid required by this cushioning technique even permits a portable liquid cushion such as for a wheel chair.

In FIG. 7 a cushion 45 is shown on the seat 46 of a wheel chair having arms 47 and a back 48. The reservoir 49 extends upward from the seat 46 along the back 48 to enable a hydrostatic head to be developed for the cushion 45 suflicient to lift the invalid free of seat 46. Conveniently the reservoir can be arranged to merge with the seat cushion in a continuous wall in the arrangement where no relative motion between the reservoir and cushion is employed. In the seat cushion application the minimum quantity of liquid for effective pressure distribution and support is establlished for the individual using the cushion by filling the reservoir and cushion with sufficient liquid to produce a head which raises the patient free of the seat. For example with a patient having a seat supported weight of one hundred and ten pounds and a seated support area of three hundred square inches, a support pressure of 0.367 pound per square inch is required. This pressure is developed in water by a head of ten inches, hence the water in the reservoir need be filled to a depth of ten inches above the support surface of the cushion. This is readily achieved by confining reservoir 49 on the outer back of the chair.

As shown in FIGS. 7 and 8, the seat cushion 45 can be made up of rubberized nylon fabric upper and lower walls 51 and 52. The panels forming walls 51 and 52 are of the same area, as is the case in the bed cushions, so that a continuous marginal seam 53 can be made and the empty envelope lies flat. Marginal flaps 54 at the sides of the seat portions are of double walled thickness and have grommets 55 through which tie tapes 56 can be passed to lift the sides of the sea-t when tied to the arms 47 of the chair. In this manner the upper wall 51 is loose due to extra material equal to twice the depth of the liquid in the seat. As shown in FIG. 8, this loose upper wall 51 conforms to the body of the patient to distribute support uniformly and avoid concentration of pressure on the body.

A seated patient to be completely supported by the displacement of liquid would be immersed up to his head where water is the liquid within the cushion. Since this is not practical, particularly where the mobility of a wheel chair is to be maintained and the added weight of the cushion must be limited, a hydrostatic head is developed to increase the pressure distributed over the supported surface of the patients body by the conforming cushion wall 51. The head of a few inches of water is provided by that portion of the envelope of cushion 45 secured at the top of the back by ties 57 which extend around the handles 58 and through grommets 59 in the marginal flap 61 at the distal portion of reservoir 49. Ballooning of the reservoir is avoided by forming webs between the opposed envelope Walls 51 and 52 to produce a series of ribs (not shown) in liquid communication with the seat cushion.

In both the bed and seat cushion utiliza-tions the quantity of filling liquid can be minimized by limiting the lateral extent of the cushion portion so that it does not balloon beyond the support area. Further, the liquid column developing the head in the reservoir can be constrained in cross section in the lower portions of the reservoir since the cross section of the column is not significant in developing the hydrostatic pressure.

The concept of a liquid impervious fabric or flexible sheet envelope having a communicating reservoir which can be oriented to develop a pool of liquid having a loose upper face to conform to a patient and distribute support without producing points of concentrated pressure either as a free surface flotation or a balancing pressure head in the liquid employed in the system to support a body lends itself to applications and forms other than those illustrated. Accordingly, it is to be understood that the present examples are to be read as illustrative of the invention and not in a limiting sense.

The several embodiments set forth above all ofier a cushion for a given region, either the area of support of a prone patient or a seat area, made up of an envelope 15, 36 or 45 having a first wall 16, 41 or 51 for supporting a body and a second wall 17, 37, or 52 adapted to be maintamed by a support surface such as mattress 14 or seat 46. The walls are joined, they directly engage each other in the illustrations as at seam 53, near their margins and are provided with at least one extension portion 20 extending beyond the support region of the cushion. The cushioned body 1s ra1sed above the underlying support surface in each embodiment by a depth of liquid within the cushion envelope at least equal to the depth displaced by the body when on the cushion. Therefore, the extension portion extends beyond the support region a distance at least equal to this depth and is supported, as by the pockets 18 or grommets 55 and the tapes 56 above the support surface a distance at least equal to this depth. Such an orientation provides thfh slagkdupper face of the cushion which conorms -o e o t flotation. y hereon to support the body by The cushion system can be provided with a reservoir as 25 or 49, which can have elevating means as 29 to facilitate the flow of liquid from the cushion to the reservoir when lowered. The embodiment of FIGS. 5 and 6 needs no separate reservoir for draining and filling the support region of the cushion and instead raises and lowers its extension portions 40 to transfer liquid to and from the region.

From the above it is evident that the system lends itself to many modifications. Accordingly, it is to be understood that the drawing and detailed disclosure are to be read as illustrative of the invention and not in a limiting sense.

What is claimed is:

'1. A cushion for a given region of a body comprising a first Wall of a flexible, liquid impervious, sheet material for supporting said body, a second wall of a flexible, liquid impervious, sheet material opposite said first wall and adapted to be mounted on a support surface, means joining said first and second Walls in a marginal portion thereof extending beyond said region to form a liquid container, a first extension and a second extension section on opposite sides of said region and within said marginal portion, each section exceeding the corresponding dimension for said given region by an amount at least equal to the depth of the liquid in said container displaced by said body when mounted on said region, and first and second means to suspend said first and second extension sections with their distal portions above said major portion of said second wall a distance at least as great as the depth of the liquid in said container displaced by said body when mounted on said region.

2. A cushion according to claim 1 wherein said suspending means includes pockets at the distal portions of said extension sections, a rail adapted to fit into each said pocket, and means to support each said rail to suspend said respective extension section.

3. A cushion according to claim 1 including a resrvoir for liquid for introduction into said cushion, and a conduit between said container and said reservoir.

4. A cushion according to claim 1 including means to raise and lower at least one of said extension sections to positions above and below the support surface for said second wall.

5. A cushion according to claim 2 adapted for use on a bed wherein said support surface is a mattress, said cushion is adapted to extend over a substantial portion of said mattress length, said extension sections are gen erally on the sides of said cushion paralleling said mattress length, and said means to support said rails is adapted to support said rail a distance above said mattress at least as great as the depth of the liquid in said container displaced by said body when mounted on said region.

6. A cushion according to claim 3 wherein said reservoir is above said container a distance sufficient to provide a liquid head in said container adequate to separate said first and second walls in all areas spaced from their joined marginal portions when said body is on given region.

7. A cushion according to claim 3 including means to raise and lower said reservoir to positions above and below the support surface for said second wall.

8. A cushioning system comprising a bed; a horizontal supporting surface on said bed; a cushion envelope; a first wall of said cushion envelope for supporting the body; a second wall of said cushion envelope opposite said first wall and adapted to be mounted on said supporting surface; means joining said first and second walls to form a liquid container; said walls being flexible, liquid impervious, sheet material and having a lateral extent at least equal to the region of the body to be cushioned; an extension section of said walls on each side of said region to be cushioned having a longitudinal dimension parallel to the longitudinal dimension of said bed and having a transverse dimension extending transverse of said bed beyond the region of the body to be cushioned V a distance at least equal to the depth of the liquid in said container displaced by said body when mounted on said region; and means to suspend said extension sections of said second wall oriented to suspend said sections parallel to the longitudinal dimension of said bed with the distal portions above said support surface a distance at least equal to the depth of the liquid in said container displaced by said body when mounted on said region.

9. A cushioning system according to claim 8 wherein said first and second walls are of the same lateral extent and said means joining said first and second walls maintains marginal portions of said walls in direct engagement whereby said first wall between said suspended extension sections presents a loose and compliant surface to said body when placed thereon and conforms to said body.

10. A cushioning system according to claim 8 including means to enable the transfer of at least one of said extension sections from a position above said support surface to a position below said support surface, said transferred portions having a liquid capacity sufficient to accommodate a quantity of liquid which when drained from said body support region of said cushion envelope permits said body to rest upon said support surface.

11. A cushioning system according to claim 8 including a liquid reservoir, means coupling said reservoir and said envelope in liquid communication, and means to alter the elevation of the reservoir between a position draining liquid into said envelope and draining liquid from said envelope.

12. A body support cushioning system comprising a chair; a substantially horizontal support surface on said chair forming a seat; a back extending generally upward from rear margin of said seat; arms extending generally upward from said margins of said seat; a cushion envelope; a first wall of said cushion envelope for supporting said body; a second wall of said cushion evelope opposite said first wall and adapted to be mounted on said seat; means joining said first and second walls to form a liquid container; said walls being flexible liquid impervious, sheet material and having a lateral extent at least equal to the region of the body to be cushioned; an extension section of said walls on each side of said region to be cushioned having a transverse dimension extending transverse of said seat beyond the region of the body to be cushioned a distance generally corresponding to the height of said arms above said seat; and means coupling the distal portion of said extension sections to said arms.

13. A cushioning system according to claim 12 including a liquid reservoir mounted on said back and extending above said first wall of said cushion envelope, and means coupling said reservoir and said envelope in liquid communication.

References Cited UNITED STATES PATENTS 1/1901 Luria 5-60 '1/1917 Hall 5--284 US. Cl. X.R. 

